Light-emitting Component

ABSTRACT

A light-emitting component a first layer stack configured to generate light, at least one additional layer stack configured to generate light, where each of the first layer stack and the at least one additional layer stack are separately drivable from one another and where an auxiliary structure is arranged between the first layer stacks and the at least one additional layer stacks.

This is a continuation application of U.S. application Ser. No.15/549,626, filed Aug. 8, 2017 which is a national phase filing undersection 371 of PCT/EP2016/052898, filed Feb. 11, 2016, which claims thepriority of German patent application 10 2015 102 105.6, filed Feb. 13,2015, each of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

A light-emitting device is defined.

SUMMARY OF THE INVENTION

In embodiments a light-emitting device is disclosed. The light emittingdevice includes a plurality of light-emitting segments having, forexample, different brightness levels, colors or shapes can beimplemented by providing the plurality of segments with separateelectrodes that can be driven by different currents via separate supplylines. Making contact separately with the segments increases theproduction complexity compared with an unsegmented light-emittingdevice.

In further embodiments a light-emitting device has a plurality ofsegments that can be driven separately from one another, which devicecan be produced easily and allows efficient operation.

In other embodiments a light-emitting device is defined. Thelight-emitting device may be, for example, a light-emitting diode, inparticular an organic light-emitting diode (OLED).

In yet other embodiments the light-emitting device extends in a verticaldirection between a first main plane and a second main plane, where thevertical direction can run transverse or perpendicular to the firstand/or second main plane. The main planes may be, for example, a topface and a bottom face of the light-emitting device. The light-emittingdevice has a planar design extending in the lateral direction, i.e., forinstance extends, at least in places, parallel to the main planes, andin the vertical direction has a thickness that is small compared with amaximum extent of the light-emitting device in the lateral direction.

In at least one embodiment, the light-emitting device comprises a firstlayer stack for generating light. The first layer stack is designed togenerate light during operation of the light-emitting device. The lightgenerated in the first layer stack in this process can be white orcolored light. In this context, the first layer stack comprises organiclayers, for example. The light-emitting device may then be in particularan organic light-emitting diode, for example. Said first layer stackdefines in particular an illuminable segment of the light-emittingdevice.

In at least one embodiment, the light-emitting device comprises at leastone additional layer stack for generating light. The at least oneadditional layer stack is designed in particular like the first layerstack to generate light during operation of the light-emitting device.Light generated in this process in the at least one additional layerstack can be white or colored light in each case. In particular, abrightness and/or a color of light generated in the at least oneadditional layer stack can differ from the brightness and/or color oflight generated in the first layer stack. In addition, a shape of alateral extent of the at least one additional layer stack can differfrom a shape of a lateral extent of the first layer stack, with theresult that in particular differently shaped illuminable segments of thelight-emitting device are formed by the layer stacks.

In at least one embodiment, the first and the at least one additionallayer stacks can each be driven separately from one another. In thiscontext, contact with the layer stacks is in particular made separately.In particular, the layer stacks are arranged such that they are not incontact with one another. A material of the layer stacks and/or athickness of the layer stacks in the vertical direction can be designedto be different from one another, for instance.

In at least one embodiment, an auxiliary structure is arranged betweenlayer stacks in each pair of adjacent layer stacks. In this regard, theauxiliary structure can be arranged, for example, in direct contact withthe layer stacks of each pair of adjacent layer stacks. For instance,the auxiliary structure completely or at least partially fills a regionbetween the layer stacks of each pair of adjacent layer stacks in thelateral direction. In particular without the auxiliary structure, saidregion between the layer stacks of each pair of adjacent layer stacks inthe lateral direction may be, during operation of the light-emittingdevice, a visible separating area which, when the light-emitting deviceis viewed vertically from above, separates respective adjacent segments.

The auxiliary structure is preferably made of, or contains, a polyamide,acrylate or epoxide. The auxiliary structure can be designed to be anelectrical insulator in this case, for example. In addition, theauxiliary structure can be designed to be translucent at least inplaces, for example. Moreover, the auxiliary structure can have alight-scattering design at least in places, for example.

In at least one embodiment, the light-emitting device comprises a firstlayer stack for generating light and at least one additional layer stackfor generating light, each of which can be driven separately from oneanother. An auxiliary structure is arranged between layer stacks in eachpair of adjacent layer stacks. Said auxiliary structure is arranged inparticular such that light passes vertically through said structure, forexample, at least in places, from one of the respective layer stacks,and/or such that said auxiliary structure couples out, at least inplaces, guided modes, and/or couples out, at least in places, lightcaptured by total internal reflection in the light-emitting device.

A light-emitting device of this type advantageously allows laterallyadjacent segments of the light-emitting device to appear connected andcontiguous to a viewer when the light-emitting device is put to itsintended use. This also has the advantage that a ratio of anun-illuminated area of the light-emitting device to an illuminated areaof the light-emitting device can be minimized, thereby contributing inparticular to efficient operation of the light-emitting device.

In at least one embodiment, a mean distance between the layer stacks ineach pair of adjacent layer stacks equals between 50 μm and 500 μminclusive, in particular between 100 μm and 200 μm inclusive. A gap ofthis size between adjacent layer stacks simplifies arranging the layerstacks laterally adjacent to one another without material from the onelayer stack coming into contact with material from the other layerstack, i.e., with this relatively large value defined for the distancesbetween the layer stacks, it is possible to drive the layer stacksindependently. The auxiliary structure described here between the layerstacks can prevent the gap being visible for the viewer, giving theimpression of layer stacks that transition seamlessly into one another.

In at least one embodiment, a mean lateral extent of the layer stacksequals between 1 mm and 100 mm inclusive. In particular, the meanlateral extent of the layer stacks is between a multiple of 5 and 2000inclusive of the mean distance between the layer stacks in each pair ofadjacent layer stacks.

In at least one embodiment, a first electrode is assigned to each of thefirst and the at least one additional layer stacks, which electrodemakes electrical contact with the associated layer stack. In addition, acommon second electrode is assigned to the first and the at least oneadditional layer stacks, which electrode makes electrical contact withthe layer stacks. The electrodes are designed in particular to injectcurrent into the respective layer stacks. One of the electrodes may herebe a light-transmissive electrode, and an electrode that is arrangedvertically opposite the light-transmissive electrode may be a reflectiveelectrode.

In at least one embodiment, each of the first electrodes contains atransparent conductive oxide (TCO). Transparent conductive oxides aretransparent conductive materials, normally metal oxides such as, forinstance, zinc oxide, tin oxide, aluminum tin oxide, cadmium oxide,titanium oxide, indium oxide or indium tin oxide (ITO). Each of saidfirst electrodes is preferably arranged in direct contact with theassociated layer stack on a surface of the associated layer stack thatfaces the bottom face of the light-emitting device.

In at least one embodiment, the second electrode is designed to bereflective. This advantageously contributes to a high light output fromthe light-emitting device. In this context, the second electrode can bemade of, or contain, a metal having a high reflectivity, for instance ametal such as aluminum or silver.

In at least one embodiment, the first layer stack and the at least oneadditional layer stack are arranged on a common carrier. Said carriercomprises in particular a substrate of the light-emitting device. Thesubstrate forms the bottom face of the light-emitting device, forexample. The substrate may be formed by a glass and/or a plasticsmaterial. In particular, the carrier can be designed to be translucentor transparent. In addition, the carrier can have a rigid or flexibledesign, for instance. The carrier can also comprise, for example, one ormore auxiliary layers for planarization of the substrate and/or forelectrical insulation of the substrate. The auxiliary layer canadditionally or alternatively have a reflective or light-scatteringdesign, for example. The auxiliary structure can comprise the auxiliarylayer, for instance, i.e., the auxiliary structure can extend betweenthe layer stacks and between the substrate and the layer stacks.

In at least one embodiment, the first layer stack and the at least oneadditional layer stack are arranged laterally adjacent to one another.This means in particular that, when the light-emitting device is viewedvertically from above, the respective visible segments are arrangedlaterally adjacent to one another. Owing to fabrication tolerances, therespective layer stacks and specifically the electrodes thereof may, forexample, be stacked vertically such that parts thereof lie one above theother, i.e., are arranged in an overlapping manner. With this in mind,the auxiliary structure is designed to be an electrical insulator, forexample.

In at least one embodiment, the first layer stack and the at least oneadditional layer stack and the electrodes thereof are arranged laterallyadjacent to one another without an overlap in the vertical direction.This advantageously can contribute to efficient production of thelight-emitting device. In addition, this can allow the surface of thelayer stacks that faces away from the respective first electrodes tohave a flat embodiment within production tolerances.

In at least one embodiment, the auxiliary structure is designed to be anelectrical insulator. This allows the first layer stack and the at leastone additional layer stack, and specifically the respective firstelectrodes, to be in a vertically overlapping arrangement. For instance,the at least one additional layer stack is arranged in a partial overlapvertically on a face of the first layer stack that faces away from thebottom face. By virtue of the auxiliary structure, which is designed tobe an electrical insulator, between the layer stacks, it can beguaranteed in particular that operation of the light-emitting device, inparticular with regard to an illuminable segment assigned to the firstlayer stack, remains largely unaffected by a first electrode assigned tothe at least one additional layer stack. In other words, when current issupplied via the first electrode assigned to the at least one additionallayer stack, light is generated solely in the at least one additionallayer stack, irrespective of light generation in the first layer stack.

In at least one embodiment, the auxiliary structure is designed to betranslucent at least in places. This advantageously allows lightgenerated in the respective layer stacks to pass through the auxiliarystructure. This can help to minimize the visible separating area betweensegments in each pair of laterally adjacent segments, in which area nolight is generated. In this regard, for example, at least part of the atleast one additional layer stack can be arranged on a face of theauxiliary structure that faces away from the carrier in the verticaldirection. In this case, for instance, light generated in the at leastone additional layer stack can pass in full vertically through theauxiliary structure, with the result that the laterally adjacentsegments appear connected and contiguous during operation of thelight-emitting device.

In at least one embodiment, the auxiliary structure has alight-scattering design, at least in places. The auxiliary structure isdesigned in particular to scatter at least some of the light generatedin the respective layer stacks. In particular, this can achieveredistribution of light generated in the respective layer stacks andcoupling-out of light captured by total internal reflection in thelight-emitting device (what are known as substrate modes or glassmodes). For instance, the auxiliary structure comprises one or morescattering layers in this context. In particular, the scattering layeris a translucent layer that appears opaque to a viewer.

In at least one embodiment, the auxiliary structure comprises amultiplicity of scattering particles and/or scattering centers forscattering the light. The scattering particles are preferably inorganicscattering particles, preferably made of a material such as titaniumdioxide or zirconium dioxide that has a high refractive index. A meandiameter of the scattering particles lies between 10 nm and 5 μm, forexample. The mean diameter of the scattering particles in particularlies between 10 nm and 100 nm inclusive and/or between 10 nm and 100 nminclusive. A suitable concentration of the scattering particles and/or alayer thickness of the auxiliary structure in the vertical direction canbe used to adjust a brightness of the light emitted by the auxiliarystructure, for example, to match a brightness of the light emitted bythe respective segments. A refractive index of the auxiliary structurecan also be adjusted in this regard.

In at least one embodiment, the auxiliary structure contains a matrixmaterial, into which the scattering particles are introduced andembedded. The matrix material may be, for example, an inorganic materialsuch as a glass, or an organic material such as a polymer. For instance,the matrix material is an epoxide, a silicone, a hybrid epoxy-siliconematerial, a polycarbonate or an acrylate. Alternatively or additionally,the matrix material can also contain, or be made of, metal oxides, sofor instance the following substances: silicon oxide (SiO₂), zinc oxide(ZnO), zirconium oxide (ZrO₂), indium tin oxide (ITO), antimony tinoxide (ATO), aluminum zinc oxide layer (AZO) or indium zinc oxide (IZO),gallium oxide (Ga₂Ox), aluminum oxide (Al₂O₃) or titanium oxide.

In at least one embodiment, the auxiliary structure is applied by apatterned process such as screen printing or inkjet printing, forinstance. In this case, the auxiliary structure can be applied, forexample, before applying the layer stacks and each of the firstelectrodes, between applications of respective adjacent layer stacks, orafter applying the layer stacks, in particular according to a desiredoverlap of the layer stacks and the auxiliary structure in the verticaldirection. Advantageously the patterned process results in only lowfabrication tolerances, for instance 20 μm, and therefore the auxiliarystructure can in particular offset fabrication tolerances such as thosearising when applying the layer stacks, for instance. For example, theuse of masks in a physical vapor deposition (PVD) process for applyingthe layer stacks can result in fabrication tolerances between 100 μm and200 μm.

In at least one embodiment, the auxiliary structure is arranged indirect contact with the layer stacks in each pair of adjacent layerstacks. The light generated in the respective layer stacks canadvantageously be redistributed and coupled-out efficiently and in acontrolled manner, for instance on the basis of a known ratio of theassociated refractive indices. This also helps to minimize a spacing ofthe respective layer stacks, or in other words a width of the separatingarea, in the lateral direction.

In at least one embodiment, the auxiliary structure completely fills aregion between layer stacks of each pair of adjacent layer stacks in thelateral direction. In this case, the auxiliary structure can be arrangedin particular in direct contact with the layer stacks of each pair ofadjacent layer stacks. A particularly high efficiency for theredistribution and coupling-out of the light generated in the respectivelayer stacks can hence advantageously be achieved. Alternatively and/oradditionally, completely filling the region in the lateral directionallows at least a complete overlap of the first layer stack and theauxiliary structure, and/or a complete overlap of the at least oneadditional layer stack and the auxiliary structure. With this in mind,the auxiliary structure is designed to be an electrical insulator, forexample.

In at least one embodiment, the first layer stack and the auxiliarystructure are arranged to overlap in the vertical direction. This hasthe advantage that light can pass vertically through at least some ofthe region between the layer stacks, allowing the visible separatingarea to be minimized. With this in mind, the auxiliary structure isdesigned to be translucent at least in places, for example. An overlapof this type also helps to achieve easy production of the light-emittingdevice, in particular with regard to fabrication tolerances. Directcontact between the auxiliary structure and layer stacks of each pair ofadjacent layer stacks, and filling completely the region between thelayer stacks of each pair of adjacent layer stacks, can hence beachieved particularly efficiently. In this context, it is possible, forinstance, for a first electrode assigned to the first layer stack tooverlap partially the auxiliary structure in the vertical direction. Anoverlap of this type of the first layer stack in the vertical directioncan here result in particular in the first layer stack and/or theassociated electrode having an inclined angle and/or surface curvature,at least in portions, with respect to the main planes of thelight-emitting device. In this case, the associated first electrode ispreferably continuous over the whole surface.

In at least one embodiment, the at least one additional layer stack andthe auxiliary structure are arranged to overlap in the verticaldirection. An overlap of this type for instance alternatively oradditionally contributes to the easy production of the light-emittingdevice.

In at least one embodiment, the layer stacks of each pair of adjacentlayer stacks are designed such that a main extension direction of theseparating area between layer stacks of each pair of adjacent layerstacks and a main extension direction of the light-emitting deviceenclose an angle between 0° and 90°, in particular between 22.5° and67.5°. A graphical symbol such as an arrow or a direction-indicatinggraphical shape of this type, for instance, is advantageously producedfor the viewer of the light-emitting device looking vertically fromabove.

In at least one embodiment, the first layer stack comprises a recess inthe lateral direction. In addition, the at least one additional layerstack extends laterally into the recess. The graphical symbol isproduced for the viewer of the light-emitting device looking verticallyfrom above advantageously in a particularly space-saving manner withregard to a light-emitting surface area of the light-emitting device.

In at least one embodiment, the light-emitting device is part of alighting unit, or the light-emitting device is the lighting unit. Thelighting unit may be a taillight of a motor vehicle or a headlamp of themotor vehicle, for example. The motor vehicle is preferably anautomobile.

In at least one embodiment, the light-emitting device comprises at leasttwo or at least four or at least six layer stacks. Alternatively oradditionally, the number of layer stacks of the light-emitting device isat most 64 or 32 or 25 or 16 or 10. In other words, the light-emittingdevice is then not a high-resolution display having a large number ofpixels.

In at least one embodiment, the light-emitting device comprises thefirst layer stack for generating light and one of the additional layerstacks for generating light, wherein each of the layer stacks isassigned one of the first electrodes, which makes electrical contactwith the associated layer stack. In addition, the second electrode isassigned to the layer stacks and makes electrical contact with the layerstacks, so that the layer stacks can each be driven separately from oneanother. The auxiliary structure is arranged in the region between thelayer stacks, with the auxiliary structure completely filling the regionin the lateral direction. In addition, the auxiliary structure has alight-scattering design, so that the region is illuminated when light isgenerated in at least one of the layer stacks. In particular in thiscase, the auxiliary structure allows light from just one of the layerstacks or from both layer stacks, for example, to be selectivelyredistributed in the region. For this purpose, for example, lightgenerated in the associated layer stack is scattered in the region, andis then emitted in particular vertically to the outside of thelight-emitting device.

In at least one embodiment, the light-emitting device comprises thefirst layer stack for generating light and one of the additional layerstacks for generating light, wherein each of the layer stacks isassigned one of the first electrodes, which makes electrical contactwith the associated layer stack. In addition, the second electrode isassigned to the layer stacks and makes electrical contact with the layerstacks, so that the layer stacks can each be driven separately from oneanother. The auxiliary structure is arranged in the region between thelayer stacks, wherein the auxiliary structure is arranged verticallyabove a partial region of the first layer stack. The additional layerstack is arranged vertically above at least one partial region of theauxiliary structure. The auxiliary structure is designed to be anelectrical insulator, so that operation of the first layer stack remainslargely unaffected by the electrode assigned to the additional layerstack. In addition, the auxiliary structure is designed to betranslucent, so that the region is illuminated when light is generatedin the additional layer stack. This has the advantage that the visibleseparating area between the first layer stack and the additional layerstack can be minimized. Light is generated in this case solely in theadditional layer stack by the supply of current via the first electrodeassigned to the additional layer stack. Light generation in the firstlayer stack is in particular performed independently thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features, embodiments and advantages are given in the followingdescription of the exemplified embodiments in conjunction with thefigures, in which:

FIGS. 1a and 2a are a schematic sectional view and plan viewrespectively of a first exemplified embodiment of a light-emittingdevice having a plurality of segments that can be driven separately fromone another;

FIGS. 1b and 2b are a schematic sectional view and plan viewrespectively of a first part of the light-emitting device according tothe first exemplified embodiment;

FIGS. 1c and 2c are a schematic sectional view and plan viewrespectively of a second part of the light-emitting device according tothe first exemplified embodiment; and

FIGS. 1d and 2d are a schematic sectional view and plan viewrespectively of a second exemplified embodiment of a light-emittingdevice having a plurality of segments that can be driven separately fromone another.

In the figures, the same reference numbers are used to denote identical,similar or equivalent elements. The figures and the relative sizes ofthe elements illustrated in the figures shall not be considered to be toscale. Indeed individual elements and in particular layer thicknessesmay be shown exaggeratedly large in order to improve visualizationand/or understanding.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

A first exemplified embodiment of a light-emitting device 1 having aplurality of segments 17, 19 that can be driven separately from oneanother is shown schematically by FIG. 1a in a sectional view and byFIG. 2a in a plan view. As FIG. 1a shows, the light-emitting device 1comprises a carrier 9, which extends in the lateral direction. Thecarrier 9 comprises in particular a substrate (not shown in greaterdetail). The light-emitting device 1 is for instance an organic layerstack having an active region designed to generate light (not shownexplicitly in the figures to simplify diagram).

In this exemplified embodiment, the carrier 9 is designed to betranslucent, i.e., comprises, for example, at least one layer made ofglass, so that light can pass through the carrier during operation ofthe light-emitting device 1. In this regard, the light-emitting device 1can have an emission direction pointing vertically towards a bottom faceof the light-emitting device 1 (known as a “bottom emitter”).

On a face of the carrier 9 that faces away from bottom face of thelight-emitting device 1 are arranged laterally adjacent to one another afirst layer stack 3 for generating light and additional layer stack 5for generating light. The layer stacks 3, 5 comprise, for example,organic semiconductor material, in particular organic layers foremitting light and for supplying charge carriers. In this exemplifiedembodiment, the material and thickness of the layer stacks 3, 5 in thevertical direction are designed to be identical, for example. In otherexemplified embodiments, the material and thickness of the layer stacks3, 5 may differ from one another, in particular with regard tocharacteristics of the light to be emitted, for instance acharacteristic such as a color.

Each of the layer stacks 3, 5 is assigned a first electrode 11, 13,which is arranged between the layer stacks 3, 5 and the carrier 9. Thefirst electrodes 11, 13 each comprise, for example, a conductive oxide,metal or metal oxide such as indium oxide, for instance. The firstelectrodes 11, 13 can have a transparent design, for example, in thiscontext. The first electrodes 11, 13 are arranged laterally adjacent toone another, for instance. In this exemplified embodiment, viewedvertically from above, the first electrodes 11, 13 are arranged inparticular congruent with the layer stacks 3, 5.

A region laterally between the layer stacks 3, 5 and/or between therespective electrodes 11, 13 is filled over its entire surface by anauxiliary structure 7. The auxiliary structure 7 is preferably made of,or contains, a polyamide, acrylate or epoxide. In this case, theauxiliary structure 7 is designed to be translucent at least in places,for example. In particular, the auxiliary structure 7 has alight-scattering design, so that a light generated in the layer stacks3, 5 and emitted into the auxiliary structure 7 is scattered by theauxiliary structure 7 such that the light is redistributed. Theauxiliary structure 7 can be designed in this respect to couple outglass modes, for example. In other words, light generated in the layerstacks 3, 5 is emitted by the auxiliary structure 7 vertically towards aregion outside the light-emitting device 1. For this purpose, theauxiliary structure 7 comprises, for example, a multiplicity ofscattering particles and/or scattering centers for scattering the light.A refractive index of said auxiliary structure 7 is in particulargreater than a refractive index of the carrier 9. In particular, anemission direction of the auxiliary structure 7 is substantially thesame as the emission direction of the light-emitting device 1.

The layer stacks 3, 5 are also assigned a common second electrode 15,which is arranged on a face of the layer stacks 3, 5 that faces awayfrom the bottom face of the light-emitting device 1 in the verticaldirection. The second electrode 15 contains in particular a conductivematerial having a high reflectivity, for instance a material such asaluminum. In this exemplified embodiment, viewed vertically from above,the second electrode 15 is arranged in particular such that the layerstacks 3, 5 are completely covered.

The first electrodes 11, 13 form, for example, anodes of the segments17, 19, and the second electrode 15 forms a cathode of the segments 17,19. By contact being made separately with the respective firstelectrodes 11, 13 and with the second electrode 15, the segments 17, 19can generate light separately from one another during operation of thelight-emitting device 1. Coupling-out light generated in the layerstacks 3, 5 through the auxiliary structure 7 means that the regionbetween the layer stacks 3, 5 that is filled laterally by the auxiliarystructure 7 is barely perceptible to a viewer as a visible separatingarea between the segments 17, 19. In fact, when only the first layerstack 3 is generating light, the first segment 17 can appear to beenlarged laterally by the auxiliary structure 7. Likewise, when only theadditional layer stack 5 is generating light, the additional segment 19can appear to be enlarged laterally by the auxiliary structure 7. Inparticular when both layer stacks 3, 5 are generating light, theseparating area between the segments 17, 19 is discernible, for example,only by a blurred coupling-out of light from both layer stacks 3, 5.

The plan view corresponding to FIG. 1a and shown schematically in FIG.2a shows the light-emitting device 1 in a condition in which no light isbeing generated in the layer stacks 3, 5. The layer stacks 3, 5, orrespectively the segments 17, 19, are shaped like an arrow in thelateral direction. The additional layer stack 5 in particular comprisesa lateral recess into which the first layer stack 3 extends. Theauxiliary structure 7 arranged in the region laterally between the layerstacks 3, 5 is discernible in this condition of the light-emittingdevice 1 as an opaque separating area, for example.

FIG. 1b shows a schematic sectional view of a first part of thelight-emitting device 1 according to the first exemplified embodiment.The first part of the light-emitting device 1 here comprises only thecarrier 9 and the auxiliary structure 7. For instance this may be thecase during production of the light-emitting device 1 when initiallyonly the auxiliary structure 7 is applied to the carrier 9. For thispurpose, the auxiliary structure 7 is applied using an inkjet orscreen-printing process, for example.

Corresponding to this figure, FIG. 2b shows a plan view of the firstpart of the light-emitting device 1. The auxiliary structure 7 is shapedhere such that the lateral region between the layer stacks 3, 5 iscompletely filled. The shape of said auxiliary structure 7 can differfrom the shape shown in FIG. 2b , for instance in the case in which thelayer stacks 3, 5 and the auxiliary structure 7 are designed to overlapin the vertical direction.

FIGS. 1c and 2c each show a second part of the light-emitting device 1according to the first exemplified embodiment. In particular, thelight-emitting device 1 is shown here without the auxiliary structure 7.During operation of only the second part of the light-emitting device 1,the separating area between the layer stacks 3, 5 is visible to a vieweras an un-illuminated area.

FIG. 1d is used to show schematically a sectional view of a secondexemplified embodiment of the light-emitting device 1 having segments17, 19 that can be driven separately from one another. As in the firstexemplified embodiment, the light-emitting device 1 comprises thecarrier 9, on the face of which that faces away from the bottom face ofthe light-emitting device 1 are arranged the first layer stack 3 and theadditional layer stack 5. Each of the layer stacks 3, 5 is assigned afirst electrode 11, 13, which is arranged in a vertical directionbetween the layer stacks 3, 5 and the carrier 9 in direct contact with,and in particular congruent with, the respective layer stacks 3, 5.

A region between the layer stacks 3, 5 and/or between the respectiveelectrodes 11, 13, is filled completely by the auxiliary structure 7,i.e., in particular in the lateral and vertical directions. In thiscase, the auxiliary structure 7 overlaps in particular the first layerstack 3 in the vertical direction. A surface of the first layer stack 3that faces away from the bottom face of the light-emitting device 1 thusincludes material of the auxiliary structure 7. The additional layerstack 5 and the first electrode 13 assigned to the additional layerstack 5 overlap the auxiliary structure 7 and the first layer stack 3 inthe vertical direction. A surface of the auxiliary structure 7 thatfaces away from the bottom face of the light-emitting device 1, inparticular the part of the auxiliary structure 7 that overlaps the firstlayer stack 3 in the vertical direction, thus includes material of theadditional layer stack 5 and/or of the electrode 13 assigned to theadditional layer stack 5.

In this case, the auxiliary structure 7 is designed to be translucent atleast in places, for example. In particular, the auxiliary structure 7is designed to be an electrical insulator, so that operation of thefirst layer stack 3 remains largely unaffected when current is suppliedvia the electrode 13 assigned to the additional layer stack 5. Forexample, a light generated in the additional layer stack 5 passesthrough the auxiliary structure 7 vertically such that the regionbetween the layer stacks 3, 5 is barely perceptible to a viewer as avisible separating area between the segments 17, 19. The auxiliarystructure 7 can here optionally have a light-scattering design, similarto the first exemplified embodiment, so that light generatedadditionally by the first layer stack 3, for example, can beredistributed and emitted by the auxiliary structure 7.

The layer stacks 3, 5 are also assigned the common second electrode 15,which is arranged on a face of the layer stacks 3, 5 that faces awayfrom the bottom face of the light-emitting device 1 in the verticaldirection.

By contact being made separately with the respective first electrodes11, 13 and with the second electrode 15, the segments 17, 19 cangenerate light separately from one another during operation of thelight-emitting device 1. By virtue of the auxiliary structure 7, theregion between the layer stacks 3, 5 that is filled laterally by theauxiliary structure 7 is barely perceptible to a viewer as a visibleseparating area between the segments 17, 19 at least as a result oflight generated in the additional layer stack 5 passing through theauxiliary structure 7. When only the first layer stack 3 is generatinglight, the first segment 17 can appear to be delimited to a lateralextent of the layer stack 3. When only the additional layer stack 5 isgenerating light, the additional segment 19 can appear to be enlargedlaterally by the auxiliary structure 7. An identical effect likewiseoccurs when both layer stacks 3, 5 are generating light.

The plan view of the light-emitting device 1 shown schematically in FIG.2d shows the light-emitting device 1 according to the first exemplifiedembodiment and the second exemplified embodiment in a condition in whichlight is being generated at least in one of the layer stacks 3, 5. Inthe region laterally between the layer stacks 3, 5, light is emittedvertically towards the region outside the light-emitting device 1, withthe result that the auxiliary structure 7 arranged there and theseparating area are not visible to the viewer.

The description referring to the exemplified embodiments does not limitthe invention. Instead, the invention includes every novel feature andevery combination of features, which in particular includes everycombination of features in the claims, even if this feature orcombination is not itself explicitly mentioned in the claims orexemplified embodiments.

What is claimed is:
 1. A light-emitting device comprising: a first layerstack configured to generate light; at least one additional layer stackconfigured to generate light, wherein each of the first layer stack andthe at least one additional layer stack are separately drivable from oneanother; and an auxiliary structure arranged between the first layerstack and the at least one additional layer stack, wherein the auxiliarystructure is electrically insulating and comprises an organic material.2. The light-emitting device according to claim 1, wherein the firstlayer stack and the at least one additional layer stack are arrangedlaterally adjacent to one another.
 3. The light-emitting deviceaccording to claim 1, wherein the first layer stack and the at least oneadditional layer stack are arranged on a common carrier.
 4. Thelight-emitting device according to claim 1, wherein the auxiliarystructure fills a region in a lateral direction between the first layerstack and the at least one additional layer stack.
 5. The light-emittingdevice according to claim 1, wherein each of the at least one additionallayer stack and the first layer stack is part of a segment of thelight-emitting device.
 6. The light-emitting device according to claim5, wherein at least two of the segments of which each of the at leastone additional layer stack and the first layer stack are a part differin their shape.
 7. The light-emitting device according to claim 5,wherein at least two of the segments of which each of the at least oneadditional layer stack and the first layer stack are a part differ intheir lateral extent.
 8. The light-emitting device according to claim 5,wherein at least two of the segments of which each of the at least oneadditional layer stack and the first layer stack are a part differ in acolor of light produced in the respective segments.
 9. Thelight-emitting device according to claim 5, wherein at least two of thesegments of which each of the at least one additional layer stack andthe first layer stack are a part differ in a brightness of lightproduced in the respective segments.
 10. The light-emitting deviceaccording to claim 1, wherein the first layer stack is arranged betweena first electrode and a second electrode, and wherein the firstelectrode and the second electrode abut the auxiliary structure.
 11. Thelight-emitting device according to claim 10, wherein the secondelectrode covers the auxiliary structure.
 12. The light-emitting deviceaccording to claim 1, wherein the auxiliary structure is reflective orlight-scattering.
 13. The light-emitting device according to claim 1,wherein the first layer stack and the at least one additional layerstack comprise at least one different material.
 14. The light-emittingdevice according to claim 1, wherein the first layer stack and the atleast one additional layer stack differ in thickness.